Some injections may provide short-term relief for knee osteoarthritis, including corticosteroids, fluid aspiration, and PRP. However, more research is needed to fully support many types of injections.

Injections for knee osteoarthritis aren’t a cure, but they could help reduce inflammation, provide pain relief, and increase your quality of life.

Keep reading to learn more about different types of knee injections, the potential benefits and risks, and what to expect during treatment.

Corticosteroids, or glucocorticoids, are the most common type of injection for osteoarthritis of the knee. They’re similar to cortisol, a hormone the body produces naturally.

Corticosteroids are injected into the affected knee joint, known as intra-articular injection. This may quickly help reduce inflammation, relieve symptoms, and increase mobility.

Guidelines from the American College of Rheumatology and the Arthritis Foundation (ACR/AF) recommend corticosteroid injections over other types of injections for knee osteoarthritis.

According to the Arthritis Foundation, corticosteroid benefits could last several months.

However, it’s important to note that corticosteroids are not a long-term solution due to their potential side effects. Some of these may include:

A doctor may recommend waiting at least 3 months between injections and limiting injections to a single joint 2–3 times yearly.

It’s important to speak with a healthcare professional before taking corticosteroids. They could recommend an alternative, more sustainable osteoarthritis treatment based on your health condition.

For example, a 2020 study found that people who underwent physical therapy for a year had better results than those who received steroid injections.

Arthrocentesis is an injection therapy that removes excess fluid from the knee joint, which may provide immediate relief from pain and swelling.

Joints are surrounded by synovial fluid. This lubricates the joint to help it move smoothly through its full range of motion. However, inflammation caused by osteoarthritis may lead to excess fluid collecting within the knee joint, leading to symptoms of osteoarthritis.

A healthcare professional may also aspirate joint fluid if they suspect you may have a joint infection, a process called synovial fluid analysis.

Side effects and complications of arthrocentesis are rare, but may include:

  • infection
  • bleeding
  • allergic reaction

PRP therapy is an injection that uses your own blood to help regenerate tissue damaged by osteoarthritis.

According to the American Academy of Orthopaedic Surgeons (AAOS), research suggests PRP may have several benefits for knee osteoarthritis, such as:

  • providing relief from swelling, pain, stiffness, and inflammation
  • increasing mobility, function, and range of motion
  • increasing quality of life

However, it’s important to note that PRP is only available as an off-label treatment for knee osteoarthritis. Researchers also agree that more studies are needed to fully support the use of PRP for knee osteoarthritis.

For these reasons, the ACR/AF don’t recommend PRP for knee osteoarthritis.

Learn more about PRP therapy for knee osteoarthritis.

Hyaluronic acid (HA) injections are a type of viscosupplementation.

HA injections may help relieve symptoms and help your knee better absorb shock by providing extra lubrication in the affected knee, according to the AAOS.

Some possible side effects include swelling, tenderness, and pain where you receive the injection.

The ACR/AF don’t recommend HA injections due to the lack of research supporting their use in treating knee osteoarthritis.

Prolotherapy is a type of injection therapy that uses a dextrose solution, a type of sugar.

A 2023 review suggests prolotherapy may help improve knee mobility, pain, and function. However, the authors conclude that more research is needed.

Similarly, the ACR/AF don’t recommend prolotherapy for treating knee osteoarthritis.

That said, the Arthritis Foundation suggests it could be a possible treatment to try if no other treatment works, as there are limited risks of possible side effects.

You can usually receive a knee injection in a doctor’s office. The procedure only takes a few minutes.

A doctor will first ask you to sit and they will position your knee. Then, they will:

  • clean the skin on your knee and treat it with a local anesthetic
  • insert the needle into your joint, which might cause some discomfort
  • inject the medication into your joint
  • remove the needle from your joint
  • place a small dressing over the injection site

A doctor may use ultrasound to help guide the needle to the best location. The procedure is rarely painful, though you may feel discomfort.

After the injection, you’ll usually be able to go straight home. A doctor may advise you to:

  • avoid strenuous activity for the next 24 hours
  • avoid swimming
  • avoid hot tubs
  • avoid prolonged exposure to something that may allow an infection to be introduced through the needle track, which should be closed up within 24 hours
  • monitor for side effects, such as an allergic reaction or an infection (swelling and redness)
  • take OTC pain relief medication to reduce discomfort

Your knee may feel tender for a few days. Ask the doctor if there are any driving restrictions.

Here are some of the pros and cons of knee injections.

Pros

  • Injections may provide immediate relief from pain and inflammation.
  • Relief may last several months.
  • In some cases, symptoms may disappear for good after one injection.
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Cons

  • They’re typically short-term solutions, and the pain will return.
  • If osteoarthritis is severe, injections may not be effective.
  • Some people don’t experience relief.
  • Over time, their effectiveness can decrease.
  • Steroid use can lead to adverse effects.
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What is the best injection for osteoarthritis in the knee?

Corticosteroid injections are typically recommended over other types of injections for knee osteoarthritis treatment.

Do knee injections work for osteoarthritis?

Some types of injections may help provide short-term relief for knee osteoarthritis, including corticosteroid injections, fluid aspirations, and PRP therapy.

Several injections may help relieve knee osteoarthritis, but they aren’t a cure. The effectiveness also varies between individuals, and some people may benefit more than others.

If your arthritis has progressed significantly, injections and other medications may no longer provide relief.

Speak with a healthcare professional about your osteoarthritis. They can help develop the best treatment plan for you.